.pic {
    width: 100%;
    display: flex;
    align-items: center;
    flex-direction: column;

    .pic_main {
        width: 1200px;
        border: 1px solid red;

        .pic_top {
            width: 100%;
            height: 400px;
            margin: 30px 0 20px 0;
            border: 1px solid black;

            img {
                width: 100%;
                height: 100%;
            }
        }

        .pic_bottom {
            width: 100%;
            height: 300px;
            margin-bottom: 100px;
            border: 1px solid black;

            img {
                width: 100%;
                height: 100%;
            }
        }
    }

}